If I don't think like that, I couldn't keep it up.
I couldn't live if I don't think like that.
ご質問ありがとうございます。
①
"If I don't think like that"＝「もし私がそう思わなければ」
"I couldn't keep it up."＝「私はやっていけない。」
②
"I couldn't live"＝「私は生きていけない」
"if I don't think like that."＝「もしそのように思わなければ。」
Example in context: "If I don't think that there is someone out there having a harder time than me, I couldn't keep on living."＝「私よりも大変な状況で暮らしている人が世間にはいる、と思わなければ、私はやっていけない。」
ご参考になると良いです！
アメリカ合衆国 
